


Changes

by ohmyfae



Category: Final Fantasy XV
Genre: Gen, Werecat Prompto, fill for the ffxv meme, might have future prompto/noctis as they get older
Language: English
Status: In-Progress
Published: 2017-05-09
Updated: 2017-05-24
Packaged: 2018-10-29 18:35:08
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 4,183
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10859706
Author URL: https://archiveofourown.org/users/ohmyfae/pseuds/ohmyfae
Summary: Prompto Argentum was created to be an elite, highly experimental form of an MT that could shift their form, at will, into the first non-human creature they ever saw.The thing is, the first animalPromptolaid eyes on happened to be a housecat.The adventures of a shapeshifting kitten Prompto! Be prepared for some serious fluff, y'all.





	1. Chapter 1

There were seventeen floors in Niflheim's primary Magitech Research Facility. Each floor specialized in engineering a new breed of enhanced humanoid soldiers, and with funding made purposely scarce, the scientists who worked on each floor fought tooth and nail to make their research bright enough, useful enough, to gain the favor of the Emperor. Competition was fierce, and the head researchers of each floor were not above a little sabotage to gain leverage over their colleagues.

Which was why when Cor Leonis infiltrated the research facility one cold, autumn morning, the head of floor fourteen gave him the keys to the second floor cells.

 _Shifters,_ said the label on the door. Cor paid it no mind, and searched the empty cells for something, anything, that he could bring back to Insomnia.

What he found was, for all intents and purposes, a child.

Magitech shifters were rarely kept in the cells at the facility itself. They were separated from each other at birth, carefully monitored and exposed to the outside world by degrees. This was due to the unstable nature of the test subjects, who were engineered with one very delicate, _quite_ dangerous design flaw.

The genetic makeup of the first non-human creature that a floor two magitech subject saw would be imprinted into the magic that ran through the subject's bloodstream, allowing them to shift, at will, into the form of that creature. Only that creature.

Dragged out into the streets of Gralea for the first time in his young life, one year old Prompto Besithia chewed at Cor Leonis' shoulder, and watched a black cat with a wide ruff at its neck hop over a fence.

Unseen by the man who held him, Prompto's eyes flashed gold.

 

\---

 

Prompto Argentum, adopted son of Marius and Ged Argentum and current Gold Star Artist in his kindergarten class, was lost.

He knew he shouldn't have changed during recess. Changing was tricky--when he shifted from awkward, bespectacled boy to tiny, bumbling kitten, he tended to get lost in his trousers for a good minute. By that point, he was usually too distracted to remember that he only had a short amount of time before the recess bell sounded again, and had a bad habit of scrambling to the door just as it locked shut for the afternoon. But it had to be done, because otherwise he'd have to find other, less effective ways of hiding from packs of marauding third-graders.

Right now, though...

Prompto whimpered, staring down at the well-tended garden below the wall he was crouched upon. He hunched his shoulders over his paws, tail fully bushed, ears twitching as people passed through the gate to his left. How on Eos had he managed to get so high in the first place? He didn't want to change back here, not when his clothes were back at the playground, and anyways, it would be hard to explain to concerned adults why there was a little boy sitting on a wall where a kitten had been moments before.

He whimpered again. It came out as a piteous rowl of distress, thin and wavering.

"Hey, now." A large face came into view, and Prompto tried to back away, only to tip over the side of the wall. Calloused hands caught him just before he fell, and lifted him up so that he was eye-to-eye with his unexpected savior.

The man who held him was in his late teens, maybe, with dark hair looped in a short braid on one side, a tattoo just below his eye, and a smile that made Prompto's fur start to settle and his whiskers tip forward.

"Who do you belong to?" he asked, checking under Prompto's chin.

" _Nobody!_ " Prompto tried to say. It came out as a chirp. The man grinned and scratched him behind the ears, Prompto's absolute _favorite_ spot. Prompto collapsed in his hands.

"Well," said the man. He straightened his shoulders against his crisp black uniform. "At least you're off the wall." He lowered his hands to the ground, and Prompto rolled off, landing on his back with his paws in the air. The man laughed and turned aside, walking through the garden towards a distant, impossibly high building.

Prompto rolled to his feet and blinked. The garden before him was wild with flowers, interesting places to hide, and shady, out of the way paths to wander. It was way too fancy to be one of the public parks Prompto went to with his family, but he had a feeling that while _boy_ Prompto would be turned away at the gate, no one would say a word against a cat doing a little exploring.

Confident in the infallibility of his new-made plans, Prompto scrambled off down the cobblestone path of Insomnia's royal gardens.

 

\---

 

Prompto hadn't gone very far before he heard it: A faint, wet choking sound, coming from somewhere behind a clump of ferns. He wriggled through an iron grate and found the source sitting against a plum tree, sniffling into his arm. The boy was about Prompto's age, with a pointed chin and dark hair, and he wore all black, just like the man who had rescued Prompto from the wall. His face was red and blotchy, and he breathed the way Prompto did after a good cry; All embarrassed hitching and desperate attempts to hold in leftover tears.

The boy looked up at the sound of rustling, then sighed when he saw Prompto.

"Oh," he said, in a stuffy voice. "We don't get cats here."

Prompto hated to see people upset, but he wasn't very good at comforting them as a boy. He always ended up saying the wrong thing, or hugging too hard, or he'd try to make a joke and everyone would stare at him. So he hung back for a second, shuffling his paws in the lush grass of the garden.

"It's ok," the boy said. He took a deep, shaky breath. "I'm not gonna hurt you. Come here." He lay down on his belly, bringing himself face to face with Prompto, and twiddled his fingers. "Come on."

Prompto walked up to him and placed both paws on the boy's forehead in what he hoped was a hug. The boy giggled.

"Wish I had a cat like you," he said, and clumsily ran a hand down Prompto's back. Prompto backed up enough to tickle him with his whiskers, and he giggled again. "I can't keep pets at home."

" _Neither can I,_ " Prompto said, but it came out as a humming trill.

"You got it easy," said the boy, still petting him. "I bet cats don't have to worry about dads, or promises. Bet _you_ can go fishing whenever you want. Bet you have _loads_ of friends."

Prompto didn't, not really, but there was no way to tell the boy now. Instead, he rolled on his back and batted at his hand. It was a trick that always made his next door neighbor smile, and it seemed to work here, too.

"Silly cat," he said. Prompto jumped onto his back, and the boy yelped. "Hey! I gotta get up sometime, you know!"

They played for a glorious half an hour, chasing each other around the ornamental fruit trees, before Prompto heard a voice call out from behind.

"Prince Noctis?"

The boy stopped, his smile shutting off like a light. "Sorry," he said to Prompto. "Guess this is goodbye."

He lifted Prompto into his arms and squeezed him gently, pressing his face to Prompto's soft black fur.

"Thanks," he whispered. Then Prompto was being set down, the boy was running off down the path, and he was left alone with the ferns and the fruit trees.

Prince Noctis, huh?

Well, Prompto didn't know much about princes, but he did know that if he could find the way home from here on his own, he'd also be able to find his way back. And who knew? Maybe, if he was lucky, Noctis would be there, too. Then neither of them would have to worry about dads who came home late or not at all, or kids who never picked them for teams at recess, or having to search for quiet, secret places just to cry.

 _It's not goodbye,_ Prompto thought, as he made his way back towards the garden gate. _Not yet._


	2. Chapter 2

“His Majesty Regis Lucis Caelum, the one hundred and thirteenth monarch of Lucis, protector of the Crystal, bearer of the Ring of the Lucii…”

“That’s Dad,” Noct whispered. He was crouching behind the curtains of a wide private balcony, peering into what he called “the weird ballroom no one dances in anymore.” Prompto was perched on his shoulder, claws sheathed in velvety paws, tail curled around his neck. He’d never seen so many people dressed-up before. His parents wore suits to work, but they were plain grey and blue. The people in the ballroom had gold braid on their shoulders, big flowing dresses, coats that went down to their thighs, and _flowers_ where their phones should have been. It looked like a dream.

Noct ignored them, and stared up at the tall, black-clad figure of the king. 

“He says they used to dance when Mom was around,” Noct said, closing the curtains. Prompto slithered off his shoulders to the cool floor of the balcony. “And they danced in _Tenebrae._ I remember. Before… you know.” He shrugged. “Maybe it’s something only Queens do.”

Prompto _didn’t_ know about Tenebrae, but he was starting to get an idea. He’d heard bits and pieces on the news, filled with words like “invasion” and “massacre.” It was around the time Prince Noctis had gotten sick, which Prompto knew because all the houses on his block hung little black flags out in their yards for _months._

The problem was, Prompto could have just _asked_ Noct. It would’ve been easy. The prince of Lucis had been transferred to his school just a few months ago, and sat only fifteen feet away from him in class. All he’d have to do is walk up to him. _Hey, Noct!_ he’d say. _I heard you liked Sailor Moon, and fishing, and your favorite color is red even though it’s supposed to be black, and your best friend is a cat. Wow, what do ya know? I’m a cat, sometimes! Wanna hang?_

Yeah. _Easy._

Noct kicked his expensive shoes against the stone railing. 

“Iggy’s teaching me to dance,” he said, “but it’s not like I’m gonna use it for anything.”

Prompto twitched his whiskers in thought, and patted the floor with both paws. Noct crouched down, grinning.

“What’s up, buddy?”

Prompto spun in a circle. “What, _you_ wanna dance?” He stood up, and dipped into a dramatic bow. “Attend, cat,” he said, in a funny, stuffy sort of accent. “The Lucian waltz.”

Noct raised his hands to the empty air, as though holding onto a railing at shoulder-height. He took a measured step forward, and Prompto jumped on his shoe and ran around his leg. 

“Not like that,” Noct said, still in the stuffy voice. “It’s _one-two-three, one-two-three,_ tell your partner how lovely their _hair_ looks in the moo-oonlight.”

Prompto trilled out a giggle and tried to follow Noct’s feet, hopping a few steps ahead as he paced the balcony in a circle.

“Why Your Grace His Duke the Cat,” Noct said, upping his ridiculous drawl. “I _must_ know the name of your tailor!” He swooped down and picked Prompto up so that they could dance properly, Prompto dangling in his hands. 

“I _hope_ you aren’t imitating _me,_ your highness.”

Noct froze, and both he and Prompto turned to stare as Noct’s friend and advisor, Ignis Scientia, wrestled with the curtains on his way out to the balcony. Prompto liked Ignis—He made a lot of jokes Prompto didn’t really get, but he was friendly in a quiet sort of way, and kept trying to feed him when he knew Prompto and Noct were playing in the garden.

“Hey, Iggy!” Noct tried to hide Prompto behind his back, but it was way too late for _that._ “I, uh.”

“Noct,” Ignis said. “You can’t bring a _cat_ to a ballroom.”

“I’m not really a cat,” Prompto told them. Of course, they didn’t understand, and Ignis just tickled him under the chin. Oh, well. 

“These things are so _boring,_ Iggy. No one does anything. And it’s not like they’ll notice.”

“I noticed,” Ignis said. He lifted Prompto out of Noct’s hold and set him down on a balcony seat. “Were you dancing?”

Noct’s face fell into a sullen glare. “No.”

“Sure looked like it.” That voice came from the curtains, and Prompto saw Gladio, Noct’s other friend, step out onto the balcony. Puberty had hit him early, and he towered over the others, awkward and unsure on long legs he wasn’t used to. “But you got the steps all wrong, Charmless.”

“Yeah?”

“Oh, yeah.” Gladio bowed to Prompto. “May I?” 

_Uh, oh._

What followed was less of a dance lesson and more of a game of slow hot-potato as each boy tried to keep Prompto as a dance partner for more than half a minute. It was a little dizzying, but Noct was laughing hysterically by the end of it, and that was what mattered. When it was over, Prompto snuck into Noct’s shirtfront, and Gladio and Ignis flanked them as they snuck off towards the elevators. 

“Wish I could take you to school tomorrow,” Noct whispered, as he dropped Prompto off at the garden gate. 

Prompto thought about it on his way home through the dark streets of upper Insomnia. It was true that no one really talked to Noct. Not like a friend, anyways. It was always questions about his dad, or what it was like being a prince, or how big his house was. Whenever Prompto looked at him from across the room, Noct just looked _bored,_ and maybe a little lonely.

_Prompto_ knew how big Noct’s house was. He’d seen his dad, hadn’t he? And he kind of knew what it was like to be a prince, after hanging out with one for so long. So he didn’t _have_ to ask those kind of questions. 

That settled it. Tomorrow, Prompto was going to talk to him. Just to say hi. Just a start. 

Besides, nothing terrible ever came out of saying _hi._

**Notes for the Chapter:**

> Next up: Something terrible.


	3. Chapter 3

Prompto huddled in the bushes of Insomnia’s School For Talented Children and watched Mrs. Tulus, the principal, talk to a large man in a white and grey jumpsuit.

“It isn’t doing any harm, I’m sure,” she said. She adjusted her funny-looking silver glasses, which tapered at the ends, and tapped her bright yellow shoes on the recess lawn. “But there are children here, and we can’t run the risk of them picking up a disease from the poor thing.”

_Disease?_ Prompto’s tail started to fluff out in indignation. He didn’t have a _disease!_ His parents took him to get his flu shots two weeks ago and everything! He almost wanted to change back and tell Mrs. Tulus off, but then that meant that he’d have to explain why he was hiding in the rose-bushes without his clothes. _Then_ he’d get kicked out of school, and he’d never get the chance to make it up to Noct again.

Noct. Prompto wished whatever magic made it possible for him to change also gave him the ability to turn back time. If he could, he’d _definitely_ do the morning over. Maybe even the night, so he could pretend to be sick and not even _go_ to school. 

It started out so well, too.

Prompto had it all planned: He had a copy of the Sailor Moon manga that Noct wasn’t allowed to read (the one with the robot girl, who was Prompto’s favorite), he’d been planning how to greet Noct in his head all night, and he even had some follow-up answers prepared. All he had to do to start was to say hi.

He should’ve known it wouldn’t be that easy.

“Hey, Noct!” he’d shouted, his voice booming in the empty courtyard behind the PE building. Noctis had stared at him like he’d grown a second head, and Prompto realized—too late—that _no one_ called him Noct at school. Prompto had just gotten so used to calling him that in his head that it slipped out. With Noct watching him, brows lowered warily, Prompto turned beet red and tried to backtrack. 

“I mean, Noctis. H-hi, I—“ Prompto extended a hand, knocked his knee against an exercise hurdle, and went flying into the dirt. Noct let out a surprised giggle and clapped his hands over his mouth. 

“You okay?” he asked. His voice was muffled through his fingers. 

“Not really,” Prompto said. He scrambled up before Noct could approach him. How had it all gone so _wrong?_ Now he was _never_ going to be able to look him in the eye _again!_ He got to his feet, ignoring the bag that had fallen beside him, and ran for it. 

He couldn’t bear to go back to class, not after that. So Prompto ducked behind a storage shed, transformed into a panicky, wild-eyed kitten, and streaked across the open recess field towards a hole in the fence. 

And right into the path of Mrs. Tulus and the Animal Control worker.

“It’s usually in this area,” Mrs. Tulus was saying. 

“Best thing I can do,” the man said, “is set up a trap overnight. Little guy’s probably runnin’ around right now, but I’ll take a look for you just in case.”

“Thank you,” the principal said. “The last thing we need here is a feral cat colony.”

“Feral?” Prompto cried. He realized, too late, that he’d accidentally said it out loud. Both Mrs. Tulus and the Animal Control guy turned to the bushes, and Prompto slowly started to back up. 

“Step back, please,” the guy in the jumpsuit said. He had a weird sort of pole with a loop in one hand, and he prodded the bushes with it carefully. The wire loop came within an inch of Prompto’s nose, and he panicked. This was it. He had to change, or run, and he wasn’t sure he could outrun Animal Control _and_ Mrs. Tulus. 

He let out a yowl of distress and bolted out of the bushes, making a straight line for the storage shed. He could feel the vibration of the man’s feet behind him, and he was so caught up in trying not to look back that he didn’t pay much attention to what was lying _ahead—_

“Got you!” 

Small hands—familiar hands, _safe_ hands—scooped Prompto up by the middle and lifted him into the air. For a second he kept flailing, and scraped a claw along Prince Noctis’ bony wrist. Noct flinched, but didn’t let go. 

“Young man!” The animal control guy, followed by Mrs. Tulus, panted to a stop a few feet away. “Hand that cat over to me, carefully. It’s feral.”

“No he isn’t,” Noct said. He brought his arms close to his chest, and Prompto gratefully climbed onto his shoulder. “He’s mine.”

“Yours?” Mrs. Tulus said. “Prince Noctis, surely not. You know we have a strict policy against bringing pets to school. Now, hand Mr. Phelan the cat, and we can—“

“I said he’s _mine,_ ” Noct said. He had the same stubborn voice Prompto heard him use with Ignis sometimes, when Noct really didn’t want to go inside and study. “His name’s… He’s Prom.”

Prompto dug his claws in reflexively, and Noct winced. _Prom?_ He looked down. Noct was… Noct was holding Prompto’s school-bag, and the zipper was undone, revealing the manga he’d planned on lending him. Prompto turned to look at the prince, who gave him a quick, not very surreptitious wink.

“We’ll have to call your father and arrange a meeting,” Mrs. Tulus said. “We can’t allow you to break the rules simply because you’re the _prince,_ your highness.”

“Yes, ma’am.” Noct fiddled with the zipper of Prompto’s bag. “Can you call my fr—my advisor, Ignis, and have him pick me up? So I can take Prom home?”

Mrs. Tulus sighed. “Very well.” 

“And I need to get something first,” Noct said. Mrs. Tulus waved him on, and Noct held onto Prompto with one hand as he made his way towards the shed. 

“You owe me _big_ time,” he whispered. Prompto tried to wriggle off his shoulders, but Noct shook his head. “Nuh-uh. One of the things you owe me is an explanation.” They reached Prompto’s discarded clothes, which Noct shoved into his bag. “If I don’t get in the car with you,” he said, “we’ll both be in trouble. And don’t freak out, I’m not mad or anything. When you ran off, I saw you left your bag, so I went after you. Then you were, uh. A cat, I guess. How do you do that?”

Prompto meowed, pointedly.

“Oh, right. Can you change back?”

Prompto nodded. “That’s good. You can do that when we get home. I’ll sneak you into my room like always, no problem.”

_No problem,_ Prompto thought, as Noct walked back to the school gate. _Right._

Ignis showed up with a chauffeur a few minutes later, looking like a stormcloud on legs. He lectured Noct the entire drive to the Citadel, even if he _did_ grab Prompto and pet him (a little angrily) at the same time. By the time they got there, Ignis had come up with a dozen different ways Noct would have to atone for bringing a cat to school, and most of them involved writing _lines._

“Sorry,” Prompto chirped, and Noct, getting his meaning, shrugged minutely. 

“No you don’t,” Ignis said, when Noct shoved Prompto into the bag. “You’re leaving him in the garden, Noctis.”

“Not _his_ fault, Iggy,” Noct said. “Come on,” he whispered softly, and held the bag up so it didn’t jostle as he booked it for the elevator. Ignis groaned in frustration behind them, and Prompto couldn’t help but feel sorry for him. He was just trying to do his job, after all, and not many people _had_ jobs when they should’ve been in middle school. 

When they got to Noct’s bedroom, the prince locked the door in his advisor’s face.

“Noctis!”

“Sorry, Iggy!”

Noct ran to the connecting bathroom and set the bag down. “Ok, you can change back,” he said. “But we’ll have to sneak out onto the roof if we wanna talk, because Iggy’s gonna try and get my _dad_. If he isn’t busy. Which he always is.”

He left Prompto alone in the bathroom, and Prompto, with no other course left to him, closed his eyes and _shifted_ until he felt at least ninety-percent human again. Then he pulled out his white uniform shirt.

“Oh, man!” he cried. “It’s all wrinkled.”

“What else was I supposed to do?” Noct called out, from the other side of the door. “Are you human again?”

“I guess.” Prompto grumbled and started doing up his shirt buttons. 

“So how do you… how do you do it?” Noct asked. “Are you a cat who turns into a kid, or is it the other way around? Why didn’t you tell me? I’ve been stuffing you in my shirt for like, months.”

“I don’t know how I do it,” Prompto said. “And I’m human. I have parents and everything. I didn’t tell you ‘cause it’s… you know. It’s _weird._ ”

“You wanna know weird?” Noct said. “My dad talks to a crystal. We have a ring with all my great great grandparents in it. I can _teleport._ That’s weird.” He was silent for a moment, and then said, a little wistfully, “Wish _I_ could turn into a cat.”

“The fleas are a problem,” Prompto admitted. He left off putting on his shoes or jacket, and opened the bathroom door. “And Animal Control.”

“Good thing you’re friends with a prince, huh?” Noct said.

Prompto paused at the door. Noct was standing at the open window, looking expectant and a little anxious. Prompto recognized it by the way he was tugging at his fingers, like Ignis did with his gloves. It wasn’t really a proper question, Prompto knew, but it _felt_ like one.

_Friends,_ he’d said.

“Yeah,” Prompto said. “Lucky me.”

Noct _beamed._

The two of them climbed out the window—Noct surefooted, Prompto testing each shingle with the caution of a kid used to apartments where snow could bring a ceiling down—and sat on the edge, kicking their heels against the white stone of the Citadel walls. Below them, the royal garden was a mess of color and swirling pathways, and Prompto felt dizzy and light-headed, like he was going to float off into the air if he leaned over too far.

“So,” Noct said. “Let’s do this over. Hey, Prom.” He extended a hand.

Prompto grinned, and took it. 

“Hey, Noct.”

 

\---------

And hey, why not: Here's a sketch of Noct and kitten!Prompto if y'all are interested. I'm not exactly an ace artist, but I was in the mood for something cute and fluffy yesterday!


End file.
